| First Author | Desgranges ZP | Year | 2005 |
| Journal | Mol Cell Biol | Volume | 25 |
| Issue | 24 | Pages | 10940-52 |
| PubMed ID | 16314517 | Mgi Jnum | J:103762 |
| Mgi Id | MGI:3610696 | Doi | 10.1128/MCB.25.24.10940-10952.2005 |
| Citation | Desgranges ZP, et al. (2005) Inhibition of TFII-I-dependent cell cycle regulation by p53. Mol Cell Biol 25(24):10940-52 |
| abstractText | The multifunctional transcription factor TFII-I is tyrosine phosphorylated in response to extracellular growth signals and transcriptionally activates growth-promoting genes. However, whether activation of TFII-I also directly affects the cell cycle profile is unknown. Here we show that under normal growth conditions, TFII-I is recruited to the cyclin D1 promoter and transcriptionally activates this gene. Most strikingly, upon cell cycle arrest resulting from genotoxic stress and p53 activation, TFII-I is ubiquitinated and targeted for proteasomal degradation in a p53- and ATM (ataxia telangiectasia mutated)-dependent manner. Consistent with a direct role of TFII-I in cell cycle regulation and cellular proliferation, stable and ectopic expression of wild-type TFII-I increases cyclin D1 levels, resulting in accelerated entry to and exit from S phase, and overcomes p53-mediated cell cycle arrest, despite radiation. We further show that the transcriptional regulation of cyclin D1 and cell cycle control by TFII-I are dependent on its tyrosine phosphorylation at positions 248 and 611, sites required for its growth signal-mediated transcriptional activity. Taken together, our data define TFII-I as a growth signal-dependent transcriptional activator that is critical for cell cycle control and proliferation and further reveal that genotoxic stress-induced degradation of TFII-I results in cell cycle arrest. |
